When should you replace a transom due to rot?
 

I decided to check my 86 scarab panther out today, I noticed up at the very top where it meets the aluminum bumper trim, and about 4 inches in from either side of the top corners, and maybe 1 to 2 inches down its dull, and it's also a bit dull around the exhaust ports. Everywhere else around the tabs, and drives is nice and solid though. Should I be too worried yet? I would like to get away with another season before diving into this thing, but I am pulling the engine this evening to upgrade to the 72c velvet drives, and I do plan on checking around the stringers.

How did you measure that? What does "dull" mean?

sorry nothing technical, just the hammer method

THanks, It's dry from what I can tell. I took a pick and tried picking around the exhaust ports, it was good and solid, and dry as a bone. It actually looked very good. I had a hull survey done and was told it was good a few years back when I bought it, but quite a bit of water built up inside it while it was parked outside this last winter, and it got me a bit nervous.